program homework;
uses CRT;


function pow(x:double; n:integer):double;
var
  i:integer;
  total:double;
begin
   total := 1.0;

   for i:=1 to n do
   begin
      total := total * x;
   end;

   pow := total;
end;

function polynom(x:double):double;
begin
   polynom := 1 - 2 * x + 3 * pow(x, 2) - 4 * pow(x, 3) + pow(x, 4);
end;

var

   x:double;

begin
   clrscr;

   writeln('Enter x: ');
   readln(x);

   writeln('Result: ', polynom(x):3:3);
   readkey;
end.